Categories: Mars

More Evidence of Liquid Erosion on Mars?

 

[/caption]

Terby Crater, a 170-km-wide (100-mile-wide) crater located on the northern edge of the vast Hellas Planitia basin in Mars’ southern hemisphere, is edged by variable-toned layers of sedimentary rock – possibly laid down over millennia of submersion beneath standing water. This image (false-color) from the HiRISE camera aboard the Mars Reconnaissance Orbiter shows a portion of Terby’s northern wall with what clearly looks like liquid-formed gullies slicing through the rock layers, branching from the upper levels into a main channel that flows downward, depositing a fan of material at the wall’s base.

But, looks can be deceiving…

 

Terby Crater. Credit: NASA/JPL/University of Arizona

Dry processes – especially on Mars, where large regions have been bone-dry for many millions of years – can often create the same effects on the landscape as those caused by running water. Windblown Martian sand and repetitive dry landslides can etch rock in much the same way as liquid water, given enough time. But the feature seen above in Terby seem to planetary scientists to be most likely the result of liquid erosion… especially considering that the sedimentary layers themselves seem to contain clay materials, which only form in the presence of liquid water. Is it possible that some water existed beneath Mars’ surface long after the planet’s surface dried out? Or that it’s still there? Only future exploration will tell for sure.

“While formation by liquid water is one of the proposed mechanisms for gully formation on Mars, there are others, such as gravity-driven mass-wasting (like a landslide) that don’t require the presence of liquid water. This is still an open question that scientists are actively pursuing.”

– Nicole Baugh, HiRISE Targeting Specialist

Terby Crater was once on the short list of potential landing sites for the new Mars Science Laboratory (aka Curiosity) rover but has since been removed from consideration. Still, it may one day be visited by a future robotic mission and have its gullies further explored from ground level.

Click here to see the original image on the HiRISE site.

Image credit: NASA / JPL / University of Arizona

Jason Major

A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

Recent Posts

The Most Dangerous Part of a Space Mission is Fire

Astronauts face multiple risks during space flight, such as microgravity and radiation exposure. Microgravity can…

9 mins ago

Stars Can Survive Their Partner Detonating as a Supernova

When a massive star dies in a supernova explosion, it's not great news for any…

3 hours ago

Swarming Satellites Could Autonomous Characterize an Asteroid

An asteroid's size, shape, and rotational speed are clues to its internal properties and potential…

9 hours ago

Officially, Only the Sun Can Have Planets. Is it Time to Fix the Definition of “Planet”?

What is the true definition of a planet, and could there be a more refined…

15 hours ago

Neutron Star is Spraying Jets Like a Garden Sprinkler

X-ray binaries are some of the oddest ducks in the cosmic zoo and they attract…

22 hours ago

NASA Stops Work on VIPER Moon Rover, Citing Cost and Schedule Issues

NASA says it intends to discontinue development of its VIPER moon rover, due to cost…

22 hours ago